Farm silo personnel elevator



Nov. 6, 1951 Filed Sept. 22, 1949 A. c. RADTKE 2,573,930 FARM SILOPERSONNEL ELEVATOR 5 Sheets-Sheet 1 FIGI.

INVENTOR ADELBERT c. RADTKE May M ATT'Y Nov. 6, 1951 A. c. RADTKE FARMSILO PERSONNEL ELEVATOR 3 Sheets-Sheet 2 Filed Sept. 22, 1949 FIGB.

INVENTOR DELBERT C. RADTKE ATT'Y.

Nov. 6, 1951 A. c. RADTKE FARM SILO PERSONNEL ELEVATOR 3 Sheets-Sheet 3Filed Sept. 22 1949 INVENTOR ADELBER T C. RADTKE' PM FIGT.

Patented Nov. 6, 1951 I FARM SILO PERSONNEL ELEVATOR Adelbert o. meme,Oak Park, 111., assignor to International Harvester Company, acorporation of New Jersey Application September 22, 1949, Serial No.117,175

This invention relates generally to an improvement in farm silos, andmore particularly to a personnel elevator especially constructed andarranged within the silo ac cess chute to readily enable the farmer toascend and descend the silo safely and quickly. v

'Farm' .silos generally have an upright access chute into which thedischarge openings of the silo proper open at different points in theheight of the silo and the access chutehas an outlet ordischargeopeningat the bottom. Heretofore, it was necessary for the farmer whenwithdrawing a quantity of ensilage from the silo to climb the interiorof the access chute to the proper discharge opening, and upon enteringthe silo take the desired quantity of ensila'ge therefrom and allow itto drop through the access chute to the outlet or discharge opening atthe bottom of the access chute. Inasmuch as it is neces--- sary to usethe silo ladder to gain access tothe silo, oftentimes the operation isdangerou'sbee cause of the accumulation of Wet ensilage 'on'the rungs ofthe ladder. Hence, the primary objective of this invention is to providea new and improved personnelelevator. for silos whereby the farmer maysafely ascend and descend the silo without using the silo ladder. lAnother object is the provision of a novel automatic safety device whicheifectively stops descent of the elevator car upon failure of thesupporting chain track. A still further object is the provision of meanswhereby the ensilage may be taken from the silo at any particularunloading point, and delivered to the bottom of the accesschute withoutthe discharge of ensilage being hampered by the ele Vator car.

A further object is the provision of novel guide means for the elevatorcar which also serves as a braking surface for an automatic safetydevice carried by the elevator car. a

The foregoing and other important objects and desirable featuresinherent in and encompassed by the invention, togetherwith many of thepurposes and uses thereof, will become readily apparent from a readingofthe ensuing description in conjunction withthe annexed drawings, inwhich: Fig. 1 is a side elevational view of a farm silo showing thepreferred embodiment of the invention positioned within the silo accesschute;

Fig. 2 is a plan view of the access chute with the top of the accesschute cut away to show the elevator car;

Fig. 3 .is a side elevational view showing the 12 Claims.

, 2 safety device and driving mechanism in detail;

Fig. 4 is a side elevational view showing the elevator platform in avertical position;

Fig. 5 is a detail view of the motor controlling switches;

Fig. 6 is a sectional view taken substantially along the line 66 of Fig.2; and

-Fig. '7 is a sectional view taken substantially along line 7--1 of Fig.2.

Referring to the drawings, in which like reference characters designatelike elements throughout the various views, a conventional farm silo I0is shown having a Vertically extending opening 1 I substantially alongthe entire height of the silo. The vertical opening H is closed by aseries of removable boards or plates l2 which may be individuallyremoved to provide a plurality of discharge openings along the height ofthe silo l0. Positioned over the vertical opening II is a substantiallysemi-circular access chute l3 having an outlet or discharge opening I 4at its bottom. A plurality of horizontal reinforcing rods or bars I5 arestructurally held in the vertical opening II to provide ladderrungs forascending or descending the silo Iil. Fastened within the access chute13 as by means of a plurality of horizontal brackets l6 secured tocertain of the bars l5 are a pair of guide rails l1 preferably formed ofangle iron strips.

An elevator car, designated generally by refer- A ence character [8, isadapted for sliding vertical movement along the guide rails I! withinthe access chute [3. The car 18 includes a semicircular back portion 19made of sheet metal or like material curved to conform to the interiorwall 20 of the access chute It. A pair of vertically extending members2| preferably having an L-shaped cross-section are secured to the backportion l9 adjacent the guide rails I! whereby the surfaces 22 ofmembers 2| will abut the surfaces 23 of the guide rails I1. The members2! depend downwardly below the lowermost edge 24 of the back portion 19and hingedly support a platform 25 upon which the elevator operatorstands when operating the elevator car [8. A pair of chains 26 have oneof their ends-fastened to platform 25 and their other ends attached to apair of hand grips 21 secured on the members 2| within the back portionis to support the platform 25 in a horizontal position as shown inFig. 1. A coil spring 59 continually urges the platform 25 to a verticalposition as shown in Figure 4. The turning force of spring 59 is of amagnitude which is easily overcome by the weight of the farmer standingupon the platform 25. It

will be appreciated from a reading of the foregoing structure that thefarmer may convenient ly stand upon the platform 25 and ascend to thelevel desired whereupon he can enter the silo l and discharge a quantityof ensilage from within. silo to the bottom of the access chute l3without being hampered by the elevator car l8 in the dischargingoperation. The platform is easily pivoted to a vertical position asshown in Fig. f when operator steps away from car removing his weightfrom platform 25 by spring 59,'and thus permits the ensilage to befreely discharged through the elevator car l8; It will be noted that theback portion I9 is curvedto allow the maximum possible discharge areathrough the elevator car l8. 1 j

The elevator car I8 is continually maintained in sliding contact withthe guide rails H by means of a plurality of vertically spaced L-shapedbrackets 28 rigidly fastened to the members 2|. One leg 29 of eachbracket 28 abuts a surface 30 opposite a surface 23 of each guide railwhereby the guide rail I1 is confined or embraced between the bracket 28and the vertically extending member 2|.

Positioned above and secured tothe elevator car I8 is a frame designatedby reference character 3| which comprises a plurality of horizontallyand vertically disposed bars 32 welded together and to the elevator carto provide a supporting structure for various parts to be describedhereinafter.

An electric motor 33 for raising and lowering the elevator car I8 ismounted on the frame 3| and is equipped with an automatic brake (notshown) which prevents rotation of the rotor shaft 34 when the motor isnot energized. A speed reducer 35 is drivingly coupled to the motor 33.by means of a belt sheave 38 keyed to rotor shaft 34, a belt sheave 31keyed to the input shaft 38 of the speed reducer, and an endless belt 39connecting the sheaves 36 and 31 Positioned adjacent the motor 33 is aself-winding reel 40 of the conventional type which automatically takesup slack in the electric cord 4|, which has one end attached to anelectric outlet (not shown) in the vicinity of the mid point of cartravel in the access chute I3. It will be noted that an electricalcircuit diagram, not shown, includes leads from the reel 40, apushbutton switch 42 and a reversing switch 43. The switches 42, 43 aremounted on a horizontal bar 44 held between the vertical members 2| nearthe top of the elevator car [8 and are normally in a circuit-openposition. It will be apparent that in order to energize the motor 33both switches must be actuated to a circuit-closed position and sincethe switches are horizontally spaced from each other it will benecessary to actuate each switch with; a different hand. Hence, a verysimple interlock device is provided which effectively prevents theelevator operator from having his hands projecting from the elevator carI8 when in motion.

The input shaft 38 of the sped reducer 35 drives an output shaft 45 at areduced speed through suitable gearing (not shown) Keyed on the outputshaft 45 is a chain sheave 45 adapted to mesh'with a chain track 47. Thechain track 4'! is anchored near the top of the access chute l3 by meansof braces 48 secured to the silo rungs l5 and depends downwardlytherefrom.

A safety device 49 is mounted on the frame 3| from falling if thesupporting chain track 41 should break or become loose from itsanchorage. The safety device 49 includes a shaft 50 horizontally mountedfor rotation in the frame 3|. Each end of the shaft 50 adjacent theguide rails I1 is provided with a cam member 5| adapted to be rotatedinto wedging engagement with the guide rails. Spaced approximatelymidway between the cam members 5| on the shaft 50 is asubstantiallyL-shaped arm 52 mounted for rotation therewith. An idler chain sheave 53is rotatably supported on one leg 54 of the arm 52.

' It will be noted thatthe rotational axis of the chain sheave 53 iscoincident with the longitudinal axis of the leg. A helical tensionspring 55 has one end 53 anchored to the frame 3| and the other endattached to the leg 51 of the arm 49. It will be apparent that thespring 55 tends to rotate the shaft 50 and, therefore, the cam members5| in a clockwise direction as viewed in Fig. 3, whereby the cam members5| act as a brake on the guide rails IT. The supporting chain track 41is trained beneath chain sheave 53, over chain sheave 46, and then overan idler chain sheave 58' rotatably supported by the frame 3|. It willbe appreciated that the weight of the elevator car l8 acting through thearm 52 will overcome the biasing action of the spring 55 and rotate theshaft 50 in a counterclockwise direction. In this position, which is thenormal operating position, the cam members 5| are rotated out of wedgingengagement with the guide rails However, it will be obvious if thesupporting chain track 41 should fail, the spring 55 will be free torotate the cam members 5| into wedging engagement with the guide rails Hto effectively stop downward movement of the elevator car I8.

Attention is drawn to the fact that the entire elevator assemblyincluding the guide rails and chain track is designed to be readilyattached or detached solely to or from the reinforcing rods or bars l5of the silo vertical opening The embodiment of the invention chosen forthe purposes of illustration and description herein is that preferredas-the result of selective tests based upon requirementsffor achievingthe objects of the invention and developing the utility thereof in themost desirable manner, due regard being had to existing factors ofeconomy, simplicity of design and construction, and the improvementssought to be effected. 7 It will be appreciated, therefore, that theparticular structural and functional aspects emphasized herein are notintended to exclude, but rather'to suggest, such other adaptations andmodifications of the invention as fall within the spirit and scope ofthe invention as defined in the appended claims.

What isclaimed is: V

1. In a farm silo personnel elevator, the combination comprising avertically extending semicircular access chute; a pair of horizontallyspaced guide rails extending substantially along 33 which effectivelyprevents the elevator car l8 the entire length of said access chute; anelevator car adapted for sliding vertical movement along said guiderails within said access chute, said elevator car including asemi-circular back portion adapted to conform to the semi-circularaccess chute, and a pair of vertically extending members secured to saidback portion adjacent said guide rails adapted to abut a first surfaceof said guide rails, said member s ha ving a platform pivotally mountedbetween their lowermo t end and a p ura ity of I--shaped aeration site":said firstsurface to confinesaid. guiderails between said membersandisaidi second; legs; a

frame: positionedv above said car; electric means: to: raise and lowersaid car. including; an. electric. motor supported on said: frame andaospeeda reducer drivingly connected tosaid motor havingan output-shaftfor drivinga first chainsheave; an automatic safetydevice mounted on,said: frame, adjacentsaid motor comprising a r tatable shaft having acam member ateach end adjacent said guide rails anda. substantiallyL-sllaped arm: rigid with. said shaft, said arm having a. secondchainsheave rotatably supported on one leg thereof and: a spring acting on;the other-leg adaptedto rotate said. cam membersin-to wedging engagementwith; said. guide railsy'and a longitudinally extending chain track.depending from an upper portion of' said. access chute adapted to betrained-beneath said second chain sheave and over said first chainsheave whereby, the:- weight of said car overcomes the action ofsaidspring and rotates saidrjshaft to; disengage said cam members. fromsaiidguide rails.

2. In; a farm silo personnel elevator, the com,-

bination comprising a longitudinally extending) accesschute; a pair oftransversely spaced, guide rails extending substantially along the,entire length of said access; chute; an elevator car adapted forlongitudinal sliding movement along said guide railswithin said accesschute; a frame positioned above said car; electric means to raise andlower saidcar including a first chain sheave driven by an electricmotor; an automatic safety device mounted onlsaid frame comprising arotatable shaft having a cam member at each end adjacent said guiderails and a substantially L-shaped arm rigid with said, shaft, said armhaving a second chain sheave rotatably supported on one leg thereof andaspring acting on the other leg adapted to rotate said cam members into:wedging engagement with said guide rails; and a longitudinally extendingchain track depending from an upper portion of said access chute adaptedto be trained beneath said second sheave and over said first sheavewhereby the weight of said car overcomes the action of said spring androtates said shaft to disengage said cam members from said guide rails.

3. In a farm silo personnel elevator, the combination comprising a pairof longitudinally extending transversely spaced guide rails; an elevatorcar adapted for longitudinal sliding movement along said guide rails; aframe positioned above said car; electric means to raise and lower saidcar including a first chain sheave driven by an electric motor; anautomatic safety device mounted on said frame comprising a rotatableshaft having a cam member at each end adjacent said guide rails and asubstantially L-shaped arm rigid with said shaft, said arm having asecond chain sheave rotatably supported on one leg thereof and a springacting on the other leg adapted to rotate said cam members intoengagement with said guide rails; and a longitudinally extendingsupporting chain track adapted to be trained beneath said second sheaveand over said first sheave whereby the Weight of said car overcomes theaction of said spring and rotates said shaft to disengage said cammembers from said guide rails.

4. In a farm silo personnel elevator, the combination comprising a pairof vertical guide rails; an elevator car adapted for sliding movement 6;along, said guide rails; a frame carried on top; of; said can m ans. toraiseand. low r.- a car including, an. electric motor drivinelyconnected; to, afirst-chain sheave; a safety device mounted. on saidframe comprisin a rot ab e Shaft having a; cam member at each endadjacent said guide rails anda substantially L-shaped arm rigid withsaidshaft, saidarm having a second chain sheave rotatably supported onone leg thereof and a spring acting on; the other leg adapted to rotatesaid cam, members into engagement with said guide rails; and a upportingchain ck;ad pt tobe trainedbenea h id con sheav a ver said firstv sheavewhereby the weight of said car rotatessaid shaft to disengage said cammembers from said ui rails,

5., In a\ farm silo personnel elevator, the com-.- bination comprisingapair of vertical guide rails; an elevator car adapted for slidingvertical movement along said guide rails; a frame carried on top of saidcar; a safety device mounted on said frame including a rotatable shafthaving a cam member at each end adjacent said guide rails and asubstantially L-shaped arm rigid with said shaft, said arm, having achain sheave rotatably supported on one leg thereof and a spring actingon the other leg adapted to rotate said cam members into engagement withsaid guide rails; and a supporting chain track adapted to be trainedbeneathsaid sheave to support said car wherebythe weight of said carrotates said shaft to disengage said cam members from said guide rails.

6. In a personnel elevator, the combination comprising a, pair oftransversely spaced longi tudinally extending guide rails; an elevatorcar adapted to move longitudinally on said guide rails a frame mountedon top of said car; a rotatable shaft transversely journalled in saidframe, said shaft having a cam member on each endadapted to normallyengage said guide rails; an arm mounted on said shaft having a chainsheave rotatably mounted thereon; and a chain adapted tobe trainedbeneath said sheave to support said car whereby the weight of said carrotates said shaft to disengage said cam members from said guide rails.

'7. In a farm silo elevator, a pair of guide rails; an elevator carmovable in said guide rails; a safety device pivotally mounted on saidcar adapted to be raised into engagement with said guide rails, saidsafety device including a shaft transversely journalled on said carcarrying an arm having a chain sheave rotatably mounted thereon, and asupporting chain track passing under said chain sheave whereby saidsafety device is normally prevented from engaging said guide rails.

8. In a farm silo elevator, the combination comprising a pair of guiderails; an elevator car movable in said guide rails; a safety devicepivotally mounted on said car, said safety device including a rotatableshaft mounted on said car having a pair of cam members on each end, anarm rigid with said shaft having a chain sheave rotatably mountedthereon, and a spring acting on said arm for rotating said cam membersinto engagement with said guide rails; and a supporting chain trackpassing around said chain sheave whereby said cam members are normallyprevented from engaging said guide rails.

9. In a farm silo personnel elevator, the combination comprisinglongitudinally extending guide means; an elevator car adapted to movelongitudinally along said guide means; a frame mounted on top of saidelevator car; means mounted on said frame to impart longitudinalmovement to said elevator car including an electric motor drivinglyconnected to a horizontal output shaft, said shaft having a first chainsheave secured thereto; a safety device mounted on said frame includinga rotatable shaft longitudinally and horizontally spaced from saidoutput shaft, said rotatable shaft having a cam member at each endadjacent said guide means and an arm rigid with said shaft, said armhaving a second chain sheave rotatably supported thereon along thelongitudinal axis, and a spring acting on said arm adapted to rotatesaid cam members into engagement with saidguide means whereby therotative axes of said first and second chain sheaves are not in parallelhorizontal planes; and a supporting chain track adapted to be trainedbeneath said second chain sheave and over said first chain sheavewhereby the weight of said car rotates said rotatable shaft to disengagesaid cam members from said guide means and the rotative axes of saidsheaves are in substantially parallel horizontal planes.

10. In an elevator, the combination comprising a pair of verticalextending guide rails; an elevator car adapted to slide on said guiderails; an open frame on top of said car; a shaft journalled in saidframe; cams carried on the ends of said shaft adapted to move into andout of engagement with said guide rails; a spring biasing said shaft tocause said cams to engage said guide rails; an arm mounted on said shafthaving an idler chain sheave rotatably mounted thereon; a chain sheavevertically spaced from said idler chain sheave; a chain to provide atrack for said driving chain sheave, said chain being anchored at oneend and trained under said idler chain sheave and over said drivingchain sheave whereby said spring is overcome and said shaft and cams arerotatated to disengage said cams.

11. In a silo having a longitudinally extending access chute, thecombination comprising a pair of transversely spaced guide railsextending substantially along the entire length of said access chute; anelevator car adapted for sliding vertical movement within said accesschute; means for' guiding said elevator car including a pair oflongitudinally extending frame members secured to said elevator caradjacent said guide rails adapted to abut a first surface of said guiderails,

and a plurality of brackets secured to said frame. members, each havinga portion adapted to abut a second surface of said guide rails wherebysaid guide rails are confined between said brackets and said framemembers.

12. In a silo having a plurality of longitudinally spaced dischargeopenings arranged along the height of the silo and a semi-circularaccess chute positioned over said openings and providing an outletopening at its bottom, the

combination comprising an elevator car adapted for longitudinal movementwithin said access chute, said elevator car including a semi-circularREFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Datev 751,328 McDonald Feb. 2, 19041,470,292 Scheunert Oct. 9, 1923

